This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2002-62359, filed Mar. 7, 2002, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to an electronic apparatus that can incorporate, for example, additional memory modules. In particular, the invention relates to a structure that diffuses the heat from memory modules to the housing of the electronic apparatus.
2. Description of the Related Art
Electronic apparatuses such as portable computers have a memory receptacle for holding additional memory modules. The memory receptacle is provided in the bottom of the housing of the electronic apparatus. The receptacle has an opening that is made in the bottom wall of the housing. It is through the opening that additional memory modules can be inserted into, and removed from, the memory receptacle. A cover that can be removed usually closes the opening. The cover usually closes the memory receptacle and protects the memory modules. It is removed from the bottom wall of the housing so that the user may remove the memory modules from, or insert them into, the memory receptacle.
Each memory module has a plurality of electronic components, each incorporating a memory chip. The electronic components may be SDRAMs that operate in DDR (Double Data Rate) mode. In DDR-type SDRAMs, data can be transferred very fast. This means that DDR-type SDRAMs consume much power and generate too large an amount of heat to neglect, while they are operating. If memory modules having a DDR-type SDRAM each are provided in the memory receptacle, the bottom wall of the housing will be locally heated with the heat the DDR-type SDRAMs.
Here arises a problem. In most cases, the memory receptacle is a closed chamber. It is partitioned from the interior of the housing to prevent dust or the like from entering the interior of the housing while the cover remains removed from the bottom wall of the housing. The heat emanating from the SDRAMs may therefore accumulate in the memory receptacle. That part of the bottom wall which lies at the memory receptacle is inevitably heated to a considerably high temperature. Hence, some measures should be taken to enhance the heat radiation from the memory modules set in the memory receptacle.
In conventional electronic apparatuses, the memory receptacle is provided in the narrow gap between the bottom wall of the housing and the printed wiring board provided in the housing. Once memory modules are placed in the memory receptacle, there is left little room for a heat sink that is made of metal and should extend between the cover and the memory modules. Any heat sink of the type hitherto known cannot be used to increase the efficiency of heat radiation from the memory modules.
A heat sink, if arranged between the cover and the memory modules, would close the memory receptacle. It would hinder the replacing of memory modules or the inserting of additional memory modules. It must be removed from the opening made in the bottom wall of the housing before the memory modules are replaced or additional memories are inserted into the memory receptacle. Further, the heat sink must be set in the opening and thermally coupled to the memory modules after the replacing of memory modules or the inserting of additional memory modules.
It would take much time and labor to replace the memory modules or to insert additional memory modules into the memory receptacle.
An embodiment of this invention is to provide an electronic apparatus in which heat can be efficiently diffused from any heat-generating component into the housing, thus preventing a local temperature rise in the housing.
According to one aspect of the invention, there is provide an electronic apparatus which comprises a housing having an outer wall; a receptacle provided in the housing and having an opening at the outer wall; a heat-generating component-contained in the receptacle and being removable from the receptacle through the opening. The opening is covered with a cover that can be removed. The cover conceals the heat-generating component. A heat-conducting sheet is interposed between the cover and the heat-generating component. The heat-conducting sheet thermally connects the housing and the heat-generating component.
The heat-conducting sheet is as thin as a film. It can therefore be interposed between the cover and the heat-generating component, even if the gap between the cover and the heat-generating component is narrow. The heat emanating from the heat-generating component can efficiently diffuse to every part of the housing through the heat-conducting sheet. This prevents a local temperature rise in the housing, particularly at that part of the outer wall at which the receptacle is provided.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The features and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.